Light & Eye Flashcards
What is light?
Electromagnetic radiation
What is the range of visible light?
400 nm - 700 nm
What are 7 ways light can interact with materials?
Reflect Absorb (transduction/emmission) Refraction Diffraction Scattering Transmission Polarization
What is Rayleigh Scattering?
The scattering of indirect sunlight in air, appearing blue
What is Mie Scattering?
The scattering of direct sunlight in air, appearing white
Why do sunsets/sunrises appear red?
There is more atmosphere for the light to travel through, more of the short wavelengths get scattered
What are 3 types of polarization?
Scattering
Absorption
Reflection
How do anti road glare glasses work?
Sunlight reflecting off the road is approximately horizontally polarized as it reaches your eyes
The glasses are polarized vertically, such that it minimizes (but not completely) the glare
What causes refraction?
The change in apparent speeds of light in material
Concave lenses ____ light from its optic axis whereas Convex lenses ____ light from its optic axis
Diverge
Converge
Plano(concave/vex) lenses have (the same/different) properties as fully (concave/vex) lenses and this effect (is/isn’t) orientation sensitive
The same
isn’t
If the bulge of a planoconvex lens increases, what happens to its focal point?
Moves closer to the lens
If the indentation of a planoconcave lens becomes more curved, what happens to the light rays?
They diverge more
If you move an object closer to a convex lens, what happens to its image? How would you change the lens to correct this?
It gets farther from the lens
Bulge the lens more
Define the following Pupil Cornea Iris Lens Sclera Retina Fovea
Pupil: hole in eye Cornea: outer layer of eye Iris: controls pupil size Lens: lens Sclera: white of eye Retina: Receptor area of eye Fovea: spot on macula of eye
What are the 6 eye muscles and what do they do?
Superior/inferior rectus: up/down
Medial/lateral rectus: left/right
Superior/inferior oblique: (anti)clockwise
True/False? The human eye is perfect, and that is why it is the main argument for intelligent design
False
What is the average field of view? What is the range of steroscopic view?
190 degrees, 110 degrees
When an image passes through the lens, is it flipped left/right or upside down?
Both
What components of the eye refract light?
Cornea and lens
How do your eyes focus on an object?
Your crystalline lens contracts/relaxes
If you move an object closer towards you, how do your eyes accommodate this change?
They bulge more
What is accommodation?
The contraction/relaxation of the ciliary muscles (connected to the lens via zonule fibres) allowing the image to stay in focus
How is presbyopia different from far sightedness?
It is related to aging
What is myopia? How is it corrected?
Near-sightedness due to elongated eyeball, concave lenses
What is hyperopia? How is it corrected?
Far-sightedness due to shortened eyeball, convex lenses
